I am currently on this part of the hall campaign. Every time I go into the cave, Ragemaw isn't up, but I walk out of the cave and it shows he is. Can anyone confirm if this is bugged or not? I realize most of you are not doing this quest but I'm asking just in case.
For a workaround try attack him with a pet (if shamans still can give commands to their elemental) or put something with aoe at his location and leave the cave (voidtentacle trinket for example) this should pull him and bring him out of the cave, assuming he doesn't reset on the way out.
But shouldn't you just loot something from the ground for this quest? i'm not sure, did this campaign few months ago